September 29 – Atomic Turbines To Full

Today’s Factismal: The first nuclear powered rocket was tested in 1965.

Though it might seem absurd, there was once a time when we were going to fly to the Moon and Mars on atom-powered wings. NASA’s Nuclear Engine for Rocket Vehicle Applications, or NERVA for short, was going to form the backbone of an interplanetary fleet of exploration and colonization vehicles. It would take crew and cargo from low Earth orbit (LEO in NASA-ese) to a space station orbiting 500 miles up. It would take colonists and their equipment from that space station up to the Moon. And, most impressively of all, it would take explorers in huge new vessels all the way to Mars, where they would spend two years at a time looking for places to establish a colony. And it would do all of this by 1977.

NASA planned to take us to Mars and beyond on atom-powered wings (Image courtesy NASA)

NASA planned to take us to Mars and beyond on atom-powered wings (Image courtesy NASA)

The reason that NERVA was able to do so much is embedded in the physics of the situation. All rocket travel is governed by an equation that was first derived in 1813, long before rockets were able to do much more than make loud bangs. The equation, which has come to be known as the Tsiolkovsky rocket equation (after the Russian scientist who derived it while living in a log cabin lit by kerosene lamps) , shows that the final speed of a rocket depends on just three things: the amount of stuff it starts with (its initial mass), the amount of stuff it ends with (its final mass), and how quickly it throws stuff away (its exhaust velocity).

A rocket, reduced to its most basic form

A rocket, reduced to its most basic form

To understand the equation, imagine that you are on roller skates and have a bag full of golf balls. If you throw a golf ball, you’ll move in the opposite direction thanks to Newton’s Third Law. The harder you throw the golf ball (the higher your exhaust velocity), the faster you’ll go. And the more golf balls you throw, the sooner you’ll get to your final speed. So using a rocket with a high exhaust velocity means that you can get a large change of speed, which means that you can go more places in the Solar System and do it faster. And nuclear rockets have extremely high exhaust velocities.

The NERVA engine (Image courtesy NASA)

The NERVA engine (Image courtesy NASA)

So why aren’t we commuting to our summer homes on Mars using NERVA? We can thank a combination of politics, budget troubles, and PR ineptitude. Apollo had been sold to the public as a race to beat the Russians to the Moon. Once we had done that, there was little political will to continue NASA’s exploration program. Though Nixon committed to the first part of NASA’s plan by building the Space Shuttle, he cut back on other parts of NASA in order to create a balanced budget. In addition, public sentiment in the 1970s was turning against nuclear power. Thanks to a series of accidents and revelations about secret nuclear testing during the 1950s and 1960s, there was a strong backlash against anything with the word “nuclear” in it. And it didn’t help that NERVAs first test had spewed radioactive material over the Los Angeles basin – nor that NASA denied both the incident and the existence of NERVA, despite bragging about them just a few years earlier.

In the end, NERVA became a footnote to rocket history much like Project Orion and the DynaSoar. Today research is focused on ion propulsion, such as that powering the DAWN probe to the asteroids. Though ion propulsion motors aren’t powerful enough to lift off of Earth, they can build up enough delta V to visit any planet and do it without the fallout of bad publicity that comes with nuclear powered rockets.

If you’d like to learn more about rockets, here’s a citizen science group that is trying to launch a man into orbit:

September 28 – Oh, Baby!

Today’s Factismal: When a baby smiles with its teeth apart and showing, the baby is frightened. When a baby smiles with its teeth hidden, the baby is happy.

The human smile is a puzzling thing. We know that we do it when we are happy, but why do we do it? And why do we smile with our teeth together when most other primates smile with them apart? And when does this behavior start? Is it programmed into us by society or is it more intrinsic?

These monkeys aren't mad - they are playing (Image courtesy Psychology Today)

These monkeys aren’t mad – they are playing!
(Image courtesy Psychology Today)

It turns out that when a typical primate smiles with its teeth apart and gums pulled up to show off the teeth, it is usually (but not always) showing aggression. And when it smiles with its teeth together or the lips down to hide the teeth, it is showing submission. The only exception to this behavior appears to be what primatologists call “rapid facial mimicry” and what parents call “making faces”. Two or more primates will grimace at each other, trying to match the other’s face, as a way of becoming better friends. (No word on if their faces ever freeze that way.)

This baby is having a good time - or is he? (Image courtesy Baby Laughter Project)

This baby is having a good time – or is he?
(Image courtesy Baby Laughter Project)

Being primates ourselves, humans exhibit many of the same behaviors. But society always adds a veneer of confusion onto the basic data, which is why scientists who study the evolution of human behavior like to watch babies – they haven’t been as influenced by social norms and show a purer response. And they’ve found that human babies tend to follow the primate rule: teeth together and gums hidden, happy baby; teeth apart and gums showing, unhappy baby. And it isn’t just babies that follow these rules; the same pattern has been observed in blind people who have never had an opportunity to see others smile.

Of course, babies do more than smile; they also laugh. And that’s another rich field for research (and a little squee). If you happen to be the parent of a young baby, then the folks at the Baby Laughter Project would like your help in finding out why babies laugh and what that tells us about how our brains develop. If you’d like to help (or just want to watch videos of laughing babies), then head over to

September 27 – Totally Super!

Just some images from tonight’s supermoon eclipse. Enjoy!

“And so it begins”

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Halfway up the mountain

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Just a sliver left before totality

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That’s not Mars; it is the Moon! The red color comes from the light of every sunrise and every sunset on Earth, simultaneously. And if that ain’t cool, I don’t know what is!

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Overexposed to show the stars by the Moon.

Special factismal – Sale on books!

In celebration of the supermoon eclipse tomorrow (and my being at FenCon), all three factismal books will be on sale at Smashwords until Halloween! That’s right – learn more about your favorite sciences (and get opportunities to do them) for half off! Just enter the coupon codes below:

BirdBrainsFactismals For Bird Brains
Did you ever wonder how many different types of reptile there are (and if any live near you)? Or orcas sound like (and if they have accents)? Or how many people are killed every year by sharks (and how many sharks are killed by people)? Then this is the book for you!
Coupon code: EC67K
Expires: 10/31/2015

healthnutsFactismals For Health Nuts
Did you ever wonder what blood types mean (and if yours is special)? Or how they name diseases(and if you can get one named for you)? Or how they stopped diseases like cholera (and if you could do it, too)? Then this is the book for you!
Coupon code: UD55U
Expires: 10/31/2015

spacecadetsFactismals For Space Cadets
Did you ever wonder how they choose the names for astronomical objects (and if you could name a few yourself)? Or what Jupiter sounds like (and if you could listen)? Or whatever happened to atomic rockets (and if you could ride along)? Then this is the book for you!
Coupon code: RH34Z
Expires: 10/31/2015

September 25 – Look! Up In The Sky!

Today’s factismal: The technical term for a supermoon eclipse is a perigee-syzygy.

Mankind has been watching the skies for millenia. And we’ve seen our share of eclipses in that time, starting with the first eclipse in recorded history was seen over Sumeria (near modern-day Iran) in 1375 BCE and going through to the “supermoon” eclipse coming up on Sunday. During that time we’ve developed some terms to describe the event (such as syzygy, or “yoked together”) and we’ve learned some things.

The Earth-Moon system, draw to scale. Notice how the Moon's orbit is slightly elliptic.

The Earth-Moon system, draw to scale. Notice how the Moon’s orbit is slightly elliptic.

We’ve learned that eclipses are caused when the Moon blocks the Sun’s light from part of the Earth (a solar eclipse) or when the Earth blocks the Sun’s light from the Moon (a lunar eclipse like Sunday’s). We’ve learned that happens because the Moon orbits the Earth in a near-perfect circle. If the Moon’s orbit were a perfect circle around Earth’s equator, then we’d have an eclipse twice every month with a solar eclipse at new moon and a lunar eclipse two weeks later at full moon. But it isn’t and we don’t. Because the Moon orbits in a tilted ellipse where it comes as close as 225,291 mi and heads out as far as 251,910 mi, eclipses are rare; we only get between two and five solar eclipses each year, and the same number of lunar eclipses. In addition, the ellipse slowly precesses around the Earth so that the close part (what astronomy wonks call perigee) doesn’t always happen at the full moon; when it does, we get a “supermoon” where the Moon appears about 14% larger than normal.

The Sun, Earth, and Moon, drawn to scale (almost - the Moon is three times as large as it should be)

The Sun, Earth, and Moon, drawn to scale (almost – the Moon is three times as large as it should be)

This month we are exceptionally lucky. The Moon will be in the right place to have an eclipse (rare) and it will happen when the moon is at its closest approach (rarer)! The last time this happened was 33 years ago, and it won’t happen again for another18 years. All told, there have been five supermoon eclipses in the past century (counting this one). So you should definitely go out and see it!

All you will need to see the supermoon eclipse is clear skies and an alarm clock. For all of North and South America, the Moon will either be in eclipse at moonrise or will goo into eclipse shortly thereafter.  And the Moon will stay in total eclipse for a good hour or so. From the start of the eclipse (when the Moon first enters Earth’s shadow) to the end will take just over five hours, so you’ll have plenty of time to see the spectacle.For folks in the Central time zone, the eclipse starts at 8:07 PM and hits totality at 9:47 PM. So skip the Simpsons and go see something truly amazing!

The perigee-syzygy will be visible over all of the Americas (Image courtesy NASA)

The perigee-syzygy will be visible over all of the Americas
(Image courtesy NASA)

If you’d like to learn more about eclipses, including if you’ll be able to see any of the four eclipses visible nextyear, then head on over to the NASA Eclipse Web Site:

September 23 – Hole Lotta Trouble

Today’s factismal: The ozone hole stretched to cover a city for the first time fifteen  years ago.

One of the great successes in pollution control was the 1992 international treaty banning the use of chlorofluorocarbons (CFCs) due to their effect on the ozone layer. Following the signing of the treaty, nations were required to change their refrigerators and hairsprays so that they didn’t use CFCs; the only exceptions were for national security. So with the pollution stopped, the problem was solved, right?

2009 Ozone Hole (Image courtesy NASA)

2009 Ozone Hole
(Image courtesy NASA)

Wrong. The problem with pollution is that it doesn’t stop doing harm just because you’ve stopped putting more trash into the atmosphere. You still have to deal with all of the junk that was put into the atmosphere before you stopped. Some environmentalists call this the “teenager’s room problem”: sure, your kid has gone to college and left his room empty – but you still have the ten years of empty soda cans, candy bar wrappers, and dirty laundry piled in the corners that need to be cleaned out before it can be turned into a sewing room. And that’s where we are with CFCs in the atmosphere. We’ve stopped adding them but we still have to wait for the ones in the air to break down and go away. And, until they do, we will have problems.

This year's ozone hole (Image courtesy MACC)

This year’s ozone hole
(Image courtesy MACC)

In 2000 we saw one example of the sort of problem we’ll have; the ozone hole grew to cover an area three times the size of the continental United States. It got so large that it covered all of Antarctica and part of South America, including the city of Punta Arenas. For two days, the residents were exposed to more UV radiation than normal. Though they haven’t reported much in the way of side effects that is because UV damage is a long-term problem (e.g., skin cancer, glaucoma) caused by a short-term exposure. Fortunately, that was the largest that the ozone hole has ever gotten; since then it has shrunken considerably.

Of course, a hole in the ozone layer isn’t the only problem we’ve got. If you’d like to help monitor air quality, then why not join NASA’s Citizens and Remote Sensing Observation Network Air Quality project?

September 22 – Nobody nose

Today’s factismal: The white rhinoceros and the black rhinoceros are almost exactly the same color.

Ah, the rhinoceros. Built like a tank, looks like a Russian weightlifter.  Thirteen feet long and weighing more than two tons, the rhinoceros or rhino for short is one of nature’s most amusing and amazing animals.  As ugly as an A-10 and even tougher, these far-ranging  critters roam across Africa and Asia, nibbling on leaves and trying to stay out of trouble. Unfortunately, trouble often seeks them out.

A black rhino, hiding in the bush (My camera)

A black rhino getting clean
(My camera)

That’s because the rhinoceros has an amazing schnozz, as the critter’s name tells you. Rhinoceros literally means “nose horn” because it’s nose has a great honkin’ horn. Like all true horns, this one is made out of keratin (the same stuff in fingernails and hair) and lacks a bony core. That huge horn plus the rhino’s general toughness has led some men who feel a little inadequate to seek out powdered rhino horn to fix their little (and I do mean little) problem. And even though that doesn’t work, it has led to the decline of the rhino. Most recently, it drove the West African Black Rhino into extinction and looks to push the Northern White Rhino after it. (Amusingly, both the white and the black rhinos are mostly grey.)

A black rhino at the local rhino wash (My camera)

A black rhino hiding in the bush
(My camera)

Even the most abundant rhino species, the Southern White Rhino, only has about 20,000 individuals who roam about in crashes of  about a dozen animals with a dominant male and several females and calves. Like any true politician, the dominant male will stake out an area by building piles of poop; he then leads the crash (or herd) from place to place as they graze on grasses and shrubs or seek out water to drink. Thanks to their thick skin and sharp horns, rhinos have very few predators in the wild; even lions prefer gnawing on the bones of dead rhinos to attacking live ones.

The one predator they do have is man. Thanks to illicit and unlawful trade in rhino horns, rhino skin, and rhino meat, their numbers are steadily declining. Though the Southern White Rhino and the black rhino have staged a bit of a comeback, even their populations are 70%-80% lower than they were just three generations ago. But you can help change that!

The only right way to hunt rhino (My camera)

The only right way to hunt rhino
(My camera)

Instead of just putting on a silly horn and trampling random people for this year’s World Rhino Day, why not help scientists prepare an area for their comeback? The Gorongosa Park in Mozambique is looking to re-introduce rhinos. But before they do that, they need to know more about the ecology of the park. You can help them with this by looking at wildlife cameras and identifying the critters you see. To learn more, safari over to: